ALiEM AIR Series | Infectious Disease 2023 Module

ALiEMU AIR Series infectious disease 2023

Welcome to the AIR Infectious Disease Module! After carefully reviewing all relevant posts in the past 12 months from the top 50 sites of the Digital Impact Factor [1], the ALiEM AIR Team is proud to present the highest quality online content related to related to infectious diseases in the Emergency Department. 6 blog posts met our standard of online excellence and were approved for residency training by the AIR Series Board. More specifically, we identified 1 AIR and 5 Honorable Mentions. We recommend programs give 3 hours of III credit for this module.

AIR Stamp of Approval and Honorable Mentions

In an effort to truly emphasize the highest quality posts, we have 2 subsets of recommended resources. The AIR stamp of approval is awarded only to posts scoring above a strict scoring cut-off of ≥30 points (out of 35 total), based on our scoring instrument. The other subset is for “Honorable Mention” posts. These posts have been flagged by and agreed upon by AIR Board members as worthwhile, accurate, unbiased, and appropriately referenced despite an average score.

Take the AIR Infectious Disease Module at ALiEMU

Interested in taking the AIR quiz for fun or asynchronous (Individualized Interactive Instruction) credit? Please go to the above link. You will need to create a free, 1-time login account.

Highlighted Quality Posts: Infectious Disease

Site	Article	Author	Date	Label
SGEM	Lumbar punctures in febrile infants with positive urinalysis – it’s just overkill	Dennis Ren, MD	December 31, 2022	AIR
EMDocs	Bacterial Meningitis	Mounir Contreras Cejin, MD	January 28, 2023	HM
ALiEM	The Febrile Infant	Corey Ziemba, MD, Justin Hacnik, MD and J.D. Cambron, DO	March 29, 2023	HM
EMCrit	Approach to CNS infection	Josh Farkas, MD	August 15, 2022	HM
Core EM	Updates in STI Care	Daniel Imas, MD	March 17, 2022	HM
REBEL EM	Short course antibiotics for Peds CAP	Marco Propersi, DO	Dec 5, 2022	HM

(AIR = Approved Instructional Resource; HM = Honorable Mention)

If you have any questions or comments on the AIR series, or this AIR module, please contact us!

Thank you to the Society of Academic Emergency Medicine (SAEM) and the Council of EM Residency Directors (CORD) for jointly sponsoring the AIR Series! We are thrilled to partner with both on shaping the future of medical education.

Reference

Lin M, Phipps M, Chan TM, et al. Digital Impact Factor: A Quality Index for Educational Blogs and Podcasts in Emergency Medicine and Critical Care. Ann Emerg Med. 2023;82(1):55-65. doi:10.1016/j.annemergmed.2023.02.011, PMID 36967275

By Chris Belcher, MD|2023-07-21T14:46:01-07:00Jul 20, 2023|ALiEMU, Approved Instructional Resources (AIR series), Expert Peer Reviewed (Clinical), Infectious Disease|

Welcome to the AIR Procedures Module! After carefully reviewing all relevant posts in the past 12 months from the top 50 sites of the Social Media Index, the ALiEM AIR Team is proud to present the highest quality online content related to related to procedures in the Emergency Department. 6 blog posts met our standard of online excellence and were approved for residency training by the AIR Series Board. More specifically, we identified 2 AIR and 4 Honorable Mentions. We recommend programs give 3 hours of III credit for this module.

AIR Stamp of Approval and Honorable Mentions

Take the AIR Procedures Module at ALiEMU

Interested in taking the AIR quiz for fun or asynchronous (Individualized Interactive Instruction) credit? Please go to the above link. You will need to create a free, 1-time login account.

Highlighted Quality Posts: Procedures

Site	Article	Author	Date	Label
Rebel EM	Intra Articular Lidocaine vs Sedation in Shoulder Reductions	Nordia Matthews, MD	30 Jan 2023	AIR
EM Docs	Video Laryngoscopy in the ED	Cameron Jones, MD	8 Aug 2022	AIR
First 10 EM	Lacerations: Does closure technique matter?	Justin Morgenstern, MD	28 Nov 2022	HM
DFTB	Regional nerve blocks module	Nicola Mulrooney, MD	7 Dec 2022	HM
EM Docs	Ultrasound Guided Regional Anesthesia for Hip Fractures	Olivia Victoriano, MD and Jacob Avila, MD	5 Dec 2022	HM
Core EM	Ultrasound Guided Lumbar Punctures	Aaron Bola, MD	31 Mar 2022	HM

(AIR = Approved Instructional Resource; HM = Honorable Mention)

If you have any questions or comments on the AIR series, or this AIR module, please contact us! More in-depth information regarding the Social Media Index.

By Chris Belcher, MD|2023-04-10T20:04:50-07:00Apr 14, 2023|ALiEMU, Approved Instructional Resources (AIR series), Critical Care/ Resus|

Welcome to the AIR Neurology 2022 Module! After carefully reviewing all relevant posts in the past 12 months from the top 50 sites of the Social Media Index, the ALiEM AIR Team is proud to present the highest quality online content related to related to neurologic emergencies in the Emergency Department. 5 blog posts met our standard of online excellence and were approved for residency training by the AIR Series Board. More specifically, we identified 2 AIR and 3 Honorable Mentions. We recommend programs give 3 hours of III credit for this module.

AIR Stamp of Approval and Honorable Mentions

Take the AIR Neurology 2022 Module at ALiEMU

Interested in taking the AIR quiz for fun or asynchronous (Individualized Interactive Instruction) credit? Please go to the above link. You will need to create a free, 1-time login account.

Highlighted Quality Posts: Neurologic Emergencies

Site	Article	Author(s)	Date	Label
EMDocs	Cauda Equina Syndrome: Why do we miss it? How to improve?	John H. Priester, MD; Mark Bisanzo, MD	13 Jun 2021	AIR
EMCrit	Spinal Epidural Abscess	Josh Farkas, MD	25 Feb 2022	AIR
Clinical Monster	Must Be Blood on the Brain	Molly Piccione, DO	3 June 2021	HM
EMCrit	Neuro emergencies in pregnancy	Josh Farkas, MD	23 Feb 2022	HM
EMCrit	Neuro-onc emergencies	Josh Farkas, MD	2 June 2022	HM

(AIR = Approved Instructional Resource; HM = Honorable Mention)

If you have any questions or comments on the AIR series, or this AIR module, please contact us! More in-depth information regarding the Social Media Index.

By Chris Belcher, MD|2023-01-10T04:14:05-08:00Jan 15, 2023|ALiEMU, Approved Instructional Resources (AIR series), Neurology|

Free Comprehensive Curriculum: Climate Change and Emergency Medicine

During the COVID-19 pandemic, a few of us interested in climate change science met through the Society for Academic Emergency Medicine (SAEM), and our group slowly expanded with the virtual world. We discussed the ever-growing number of climate publications and scholarship opportunities available. Some of us did research, education, or policy work, and all of us practiced clinically.

Negative climate-related impacts that we see in the Emergency Department

We discussed how climate-related impacts negatively affected our patients, and brainstormed how we could tackle the problem now. For us in Rhode Island, Pennsylvania, Wisconsin, Colorado, and California, the climate crisis was pathology and interrupted treatment regimens, but also an opportunity to transform current care systems. At all of our hospitals, patients were brought in by ambulance with empty inhalers and non-functioning medical devices after losing electrical power. Monitors beeped from abnormal vital signs of patients impacted by extreme heat, inland and coastal flooding, or wildfires. We recognized the dangers related to place of residence and structural drivers that exacerbated existing health disparities. We agreed that open access education was the next step to action and striving for justice across our nation together.

How to start your climate change learning and advocacy journey?

More and more colleagues asked us where they could begin their own climate and emergency medicine journeys. We used our varied local and global experiences to curate content that could be used for journal clubs, medical simulation, quality improvement projects, grant applications, and other educational tracks or electives. Our goal was to provide a starting place for individuals who may not have dedicated faculty at their institutions.

Get caught up: Comprehensive 10-module curriculum

We are proud to announce a comprehensive 10-module curriculum on Climate Change and Emergency Medicine (EM) worth 56 hours of ALiEMU learning credits. Each module encompasses a broad range of reading materials and is followed by a brief quiz on ALiEMU. All of this is available for free. Get learning now.

Go to the CLIMATE CHANGE & EMERGENCY MEDICINE course home page

Be a climate changemaker

We hope the material reminds all of us of what actions are needed yet: authentic partnerships, clear communication of the robust evidence that we know, inclusivity, and leadership. Like emergency medicine, climate change and health work is truly life-long learning. Yet, knowledge is only as good as its use. We look forward to years of innovative solutions that move beyond dialogue and meaningfully address some of the greatest barriers to well-being for our patients and global community.

By Caitlin Rublee, MD MPH|2022-12-13T14:27:20-08:00Dec 14, 2022|ALiEMU, Environmental, Medical Education|

PEM POCUS endotracheal tube confirmation badge

Read this tutorial on the use of point of care ultrasonography (POCUS) for confirmation of endotracheal tube (ETT) placement in pediatric patients. Then test your skills on the ALiEMU course page to receive your PEM POCUS badge worth 2 hours of ALiEMU course credit.

Take the ALiEMU PEM POCUS: Pediatric ETT Confirmation Quiz

Module Goals

List indications for performing airway/lung POCUS to confirm ETT placement
Describe the technique of performing airway and focused lung POCUS
Distinguish between normal and abnormal airway and lung POCUS findings
Distinguish between tracheal, endobronchial, and esophageal placement of ETT
List the limitations of airway and lung POCUS

Case Introduction: The Postictal Toddler

Joey is a 2-year-old male with a history of epilepsy who presents to a community hospital emergency department with generalized tonic-clonic seizures of more than 45 minutes duration. After receiving 2 doses of IV midazolam, he stopped seizing. He has very shallow breathing and oxygen saturations as low as 90 percent on 2 liters of supplemental oxygen via nasal cannula. The pediatric transport team arrives to transport him to another hospital for admission and note that he is somnolent with poor respiratory effort. His current vital signs:

Vital Sign	Finding
Temperature	37.0 C
Heart Rate	115 bpm
Blood Pressure	85/65
Respiratory Rate	12
Oxygen Saturation (room air)	92% on 2 L via nasal cannula

An end tidal carbon dioxide (ETCO2) monitor shows a ETCO2 level in the high 70s mmHg. The decision is made to intubate the patient given disordered breathing, hypercapnia, and hypoxia following medical management of seizures. The transport team would like to use POCUS to evaluate ETT placement at the outside hospital and during transport.

For simplicity, this module will focus on 3 modes of using POCUS for ETT confirmation. Collectively, these techniques can help improve evaluation.

Indications and Benefits for ETT Confirmation by POCUS

There are many benefits of using POCUS to confirm ETT placement, such as in the following examples:

When compared to auscultation, POCUS ETT can be done in a loud environment where auscultation may be challenging (i.e., as may occur in transport or on scene).
When compared to radiography, POCUS ETT can be done rapidly at the bedside when chest radiography may be delayed or unavailable (i.e., in transport or during chest compressions).
When compared to capnography, POCUS ETT is helpful in scenarios of low pulmonary blood flow as in cardiac arrest or with poor tissue perfusion when capnography may be less reliable. Also POCUS can distinguish between tracheal and endobronchial ETT placement, whereas capnography cannot.
Unlike auscultation and capnography, POCUS ETT can confirm placement in real time, even before ventilating the patient, unlike auscultation and capnography to work.
POCUS ETT should typically be used as an adjunct to other methods of confirmation or in resource-limited settings, if other methods are not available.

Just as all methods of confirming ETT placement have their limitations, so does POCUS. This will be discussed in greater detail later in the module.

Technique

There are many factors to consider in the performance of ETT POCUS:

Factor	Options
Probe selection	Linear or curvilinear
Location on the anterior neck	Suprasternal notch, cricoid, or thyroid cartilage
Probe orientation	Longitudinal or transverse plane
Timing	Dynamic (while intubating) or static (for confirmation)
Evaluation technique	Direct (visualize the ETT) or indirect (visualize lung movement0

Probe Selection

Two types of probes will be needed for POCUS ETT confirmation.

Use a linear probe to visualize the superficial airway and lung structures. The linear probe uses high frequency sound waves to create high resolution images of superficial structures such as the trachea and pleura.
Use a curvilinear probe to visualize deeper structures, such as the diaphragm. The curvilinear probe uses lower frequency sound waves to create higher resolution images of deeper structures.

Figure 1: Linear probe (left) and curvilinear probe (right)

Timing of Image Acquisition

If time permits, pre-scan the patient’s neck to locate the trachea. Adjust the gain and depth accordingly to visualize the trachea clearly in the middle of the screen.

1. Direct Confirmation: Visualize the ETT in the Trachea

pocus neck trachea endotracheal tube ett

Figure 2: Positioning and ultrasound images of the anterior neck anatomy for ETT placement confirmation. Left: Transverse orientation of the linear probe just above the suprasternal notch. Center: Corresponding pictorial display of the trachea and surrounding structures. Note that below the trachea is a dirty shadow artifact, resulting from the air-mucosa interface. Right: Corresponding ultrasound image of the thyroid lobes flanking the empty trachea, with the ovoid esophagus seen posterolaterally (ultrasound image by Jade Sequin).

1. Static Assessment

We recommend using the static assessment (i.e., after the patient is intubated), rather than dynamic (i.e., watching the ETT enter the trachea in real time) which is technically more challenging.
Positioning: Stand at the patient’s waist, facing the patient’s head, with the probe marker pointing towards the patient’s right (transverse plane) to confirm ETT placement in the neck. Place the linear transducer midline on the anterior neck, slightly above the suprasternal notch (figure 2, left). The orientation of the image on the screen corresponds to the probe direction. This orientation is helpful for procedural POCUS and conceptually allows for easier redirection.
Identify the trachea: The trachea is visible in the midline as a semicircular structure with a hyperechoic bright line (upside down U) and shadows distally (figure 2, center). Shadows are reverberation artifact from the air in the trachea (often called “dirty shadows,” or referred to as the air-mucosa interface). The thyroid overlies the trachea as a homogenous structure with the lobes extending bilaterally.
Identify the esophagus: The esophagus is generally posterolateral and to the left of the trachea. The esophagus is seen as a collapsed round or oval shaped structure with concentric layers, without air in it (figure 2, right).
- Anatomy variability: A pediatric study noted that the esophagus can be seen in variable locations in relation to the cricoid ring and trachea. It was partially to the patient’s left (62%), completely to the left (20%), behind the cricoid ring (16%), and partially to the right (2%) [1].

When the ETT is placed correctly in the trachea, you should still see only a SINGLE air-mucosa interface, similar to an empty trachea. An ETT properly positioned in the trachea will have a similar ultrasonographic appearance with one air-mucosal interface as the air-filled tube will be in the trachea and the esophagus will be decompressed without air (figure 2, right).

2. Dynamic Assessment

Dynamic assessment involves watching the ETT pass into the trachea in real-time. In this technique, you will see a brief disturbance within the trachea termed the “snowstorm” which is a subtle finding (Video 1). A dynamic assessment is made more challenging with the multiple tasks and personnel at the bedside during intubation.

Video 1: Dynamic assessment of ETT placement confirmation using a linear probe in the transverse orientation on the anterior neck . With the probe marker to the patient’s right, the trachea is often on the left of the screen in relationship to the esophagus, as in this video. As the ETT enters the trachea, there is a slight disruption termed a “snowstorm” noted in this dynamic view. Video credit: Jade Sequin

Erroneous Esophageal Intubation

If the ETT is placed incorrectly in the esophagus, there will be TWO air-mucosa interfaces with reverberation artifact and posterior shadowing. This has been called the “double trachea sign” or “double tract sign” (figure 3, left). Contrast this to normal anatomy with an empty esophagus (figure 3, right).

Figure 3. Left: Double tract or double trachea sign on ultrasound, visualized when the ETT is placed incorrectly in the esophagus. Note the esophagus appears curved with dirty shadow artifact like the trachea. Right: Normal collapsed esophagus. Images credit: Jade Sequin.

Video 2: Esophageal intubation seen on ultrasound. Note the ETT entering the esophagus, generating the “double tract” or “double trachea” sign. Video used with permission by authors of [2].

Video 3: “Double tract” or “double trachea” sign and esophageal de-intubation. The video starts with the ETT in the esophagus, but then is removed. Video used with permission by authors of [2].

2. Indirect Confirmation: Visualize Bilateral Lung Sliding

This indirect visualization method uses ultrasound to identify bilateral lung sliding as a means to confirm ETT placement, because this implies that both lungs are ventilated. This method is often used in conjunction with and after direct confirmation using POCUS, seeing the ETT in the trachea.

If the ETT is in the right main stem bronchus, ONLY the right lung will have sliding.

Ultrasound Probe Placement

Place the linear transducer on the superior, most-anterior chest wall in the mid clavicular line over the 3rd-5th intercostal space. Ensure that the probe marker is towards the head. Scan both lungs (Figures 4).

Figure 4. Positioning of the linear probe on the patient’s anterior chest wall to check for lung sliding

Normal Lung Findings on POCUS

Figure 5. Ultrasound of a normal lung: Just deep to the chest wall and ribs, the pleural line of the lung slides horizontally to and fro with each breath.This line is the first hyperechoic line deep to the rib and is the place to look for lung sliding.

Alveoli filled with air have the ARTIFACTS that are the hallmark of airway POCUS.

A lines (figure 6): Hyperechoic lines that are parallel to the pleural line (typically horizontal) that are caused by reverberations between the pleura and transducer. They are equidistant from the chest wall. A lines are seen with normal aerated lungs along with lung sliding
Z lines or comet tails: Perpendicular lines to the pleura (often appear vertical as the pleura is typically visualized as horizontal) that arise from the pleura. These lines typically do not go to the bottom of the screen.
Lung sliding (figure 8): Shimmering artifact of the parietal and visceral pleura sliding against each other. Lung sliding indicates that the lung visualized under the probe is filled with air and ventilated (video 4).

Figure 6. Normal lung with A lines – The most superficial hyperechoic line below the chest wall is the pleural line. The subsequent hyperechoic lines parallel and deep to the pleural line are A lines. A lines are always normal findings.

Video 4: Normal lung ultrasound: Most superficial are the chest wall tissue and 2 ribs (the circular anechoic structures). The hyperechoic line just deep to the ribs is the pleural line. Lung sliding is the subtle movement at the pleural line, referred to as “ants marching.” The hyperechoic lines horizontal and parallel to the pleural line are A lines, and the thin vertical lines are Z lines, or comet tails.

B Lines

In contrast to A lines, B lines may be visualized in patients with abnormal lungs. B lines are hyperechoic lines (typically vertical) that arise at the pleural line and go all the way to the bottom of the screen (at least 4-8 cm depth with some experts recommending to 16 cm). This is in contrast to Z lines which do not go to the bottom of the screen. The presence of multiple B lines indicates increased fluid in the interstitium of the lungs, which can be seen in conditions such as bronchiolitis and pulmonary edema (figure 7, videos 5 and 6). Note that the presence of B lines also indicate aerated lungs.

Figure 7. Lung POCUS showing A and B lines. A lines are the hyperechoic lines parallel to the pleural line. B lines are the hyperechoic projections perpendicular to the pleural line that extends to the bottom of the screen. A lines are normal, while multiple B lines may be pathogenic.

Video 5: Lung ultrasound showing multiple hyperechoic, perpendicular B lines.

Video 6: Lung ultrasound showing lung sliding and multiple B lines. Note that this image uses a curvilinear probe.

M-Mode Setting

For additional confirmation of lung sliding, press the M mode button (motion mode) without lifting the probe to visualize motion of the sliding pleura. The M-mode view represents a small narrow slice of the ultrasound image (where the bold white vertical line appears) and runs only that portion over time.

Lung is aerated: Looking below the pleural line level ,you will see a grainy display, known as the “sandy beach” or “seashore” signs (figure 8). You’ll find yourself feeling very relaxed when you see this, because this indicates a successfully aerated lung.
Lung is NOT aerated: Looking below the pleural line level, you will see multiple horizontal bar-like, striated lines instead of the grainy, sandy beach (figure 9). This is called the “barcode” or “stratosphere” sign, and may be seen in a pneumothorax or a main-stem bronchus intubation.

Figure 8: Lung ultrasound with M-mode view in a normal, aerated lung (left), showing the grainy, “sandy beach” appearance of the lines deep to the pleural line. Contrast this to an abnormal, non-aerated lung (right), showing the horizontal “barcode” appearance of the lines deep to the pleural line.

Figure 9: Another example of a normal (left) and non-aerated (right lung) in M-mode view

Ultrasound Technique

Visualize lung sliding in both 2D (also known as B mode and is the typical ultrasound mode) and M mode on the both the left and right chest.

Note: If the ETT is in the right mainstem bronchus, you may still see subtle movements of the pleural line on the left due to cardiac activity. The lung sliding in this case will be asymmetric with less movement of the pleural line on the left compared to right.

Alternative Causes for Abnormal Lung Sliding After Intubation

Abnormal lung sliding on ultrasound may be worrisome for an esophageal intubation, because the lungs are not aerated with PPV breaths. However, there are other causes to consider before removing the ETT for a re-intubation attempt.

1. Pneumothorax

In order to see lung sliding, visceral and parietal pleural need to be touching. With a pneumothorax, there is air in the pleural space. The parietal pleura will still be visible, but the visceral pleura and moving interface are not seen. In the M-mode view, a “barcode sign” will be present (figure 10), highlighting the importance of evaluating both 2D (B mode) and M mode if there is any doubt about lung sliding.

Figure 10: Lung POCUS demonstrating no lung sliding (“barcode sign”) in M-mode view

Video 10: Lung POCUS of a patient with a pneumothorax, showing no lung sliding for one lung in 2D view (B mode)

2. Main stem bronchus intubation

If there is no lung sliding in just one lung (especially if it occurs on the left), this may be caused by the ETT being too deep into a mainstem bronchus. This results in non-ventilation of the contralateral lung. Be aware that since the visceral and parietal pleural are still touching (unless there is also a pneumothorax), you could see some sliding movement, as the heart still causes some movement of the lungs.

3. ETT obstruction or apnea

This results in the loss of lung sliding bilaterally.

Take Away

When you see symmetric lung sliding on both sides of the chest, the ETT is in good position in the trachea.

3. Indirect Confirmation: Visualize Diaphragm Movement

Ultrasound Probe Placement

Use a curvilinear probe, because it gives you deeper tissue penetration than the linear probe. This allows you to better visualize the diaphragm, which is a deeper structure.

Figure 11. Left: Using a curvilinear probe with the probe marker towards the head, position it along the mid-axillary line to identify the diaphragm. Continue sliding the probe to the lower edge of the ribcage until you see the diaphragm meeting the spine along the bottom of the ultrasound image. Right: Ideal ultrasound view of the hyperechoic diaphragm. Also seen is the liver with mixed echotexture, a hypoechoic kidney, and the hyperechoic spine.

Normal Findings on POCUS (figure 11)

The diaphragm is a hyperechoic line, seen curving vertically on the screen, with a solid organ (liver or spleen) caudal to that.
The spine appears as interrupted hyperechoic structures (vertebral bodies), extending caudally from the diaphragm at the bottom of the image. The vertebral bodies shadow as all calcified structures on ultrasound do. Normally the spine is only visualized caudal to the diaphragm, because aerated lung obscures visualizing the spine in the thorax (cephalad to the diaphragm).

Ultrasound Technique

Watch the movement of the diaphragm. In a patient who is paralyzed for intubation, the diaphragm will only move with delivery of positive pressure ventilation (PPV).
- Normal: If the ETT is in good position, with a PPV breath, the diaphragm moves caudal toward the abdomen as the lungs inflate, and upwards when the lungs deflate (video 7). In M mode, normal diaphragm movement creates a smooth wave with inspiration and expiration (video 8).
- Esophageal intubation: The diaphragm moves in the reverse direction than is expected. With a PPV breath, the diaphragm moves cephalad, because the abdominal cavity is getting inflated.
- Mainstem bronchus intubation: The diaphragm on the side of the main stem intubation (typically right) will show exaggerated motion toward the abdomen during PPV. The diaphragm on the contralateral side, where the lung is not properly ventilated will either not move or move paradoxically cephalad during PPV. In M-mode, there is no sinusoidal, wave pattern for the diaphragm in the non-ventilated lung (video 9)

Video 7: Ultrasound view showing diaphragmatic movement with regular breaths. The diaphragm pushes the spleen and kidneys caudal into the abdomen (to the right of the screen) with each breath.

Video 8: Ultrasound M-mode view of the diaphragm with regular breaths. Normal diaphragmatic movement is demonstrated by the hyperechoic sinusoidal line (at 12 cm depth) at the bottom of the screen.

Video 9: Ultrasound of the diaphragm in M-mode setting. The hyperechoic diaphragm does not move either in 2D (top) or M mode (bottom). This could be seen if the ETT is in the esophagus or in a mainstem bronchus, for example.

Abnormal Findings While Assessing Diaphragmatic Movement

1. Hemothorax or pleural effusion

Best seen at the costophrenic angle because fluid is dependent, a hemothorax or effusion will appear anechoic or hypoechoic. Additionally the spine can now be seen cephalad to the diaphragm, known as the “spine sign,” because air now no longer obscures the view of the spine (figure 12). A hemothorax and pleural effusion can look the same on POCUS. The clinical scenario aids in determining the potential cause of the fluid.

Figure 12. Left: Normal lung showing the spine only caudal to the hyperechoic diaphragm. Right: Hemothorax on lung POCUS. Right: Lung POCUS showing a pleural effusion, suggested by the hypoechoic fluid collection and “spine sign”.

Take Away

In a patient paralyzed for intubation and thus with no spontaneous respirations, the ETT is in good position when you see movement of the diaphragm towards the abdomen on both sides of the chest with PPV.

Proposed Algorithm for POCUS ETT Confirmation

Lin et al. published a systematic review of bedside ultrasound for tracheal tube verification in pediatric patients. The authors proposed the following algorithm (figure 13) for confirming ETT placement.

Figure 13: Algorithm for using and interpreting POCUS to confirm ETT placement in pediatric patients. Image permission granted by author of [3].

Limitations

Operator dependent: As with all POCUS studies, image acquisition and interpretation is operator dependent. The more you practice the concepts and techniques in this module, the more comfortable you will be in obtaining and accurately interpreting these images.
Challenging anatomy: It is difficult to perform airway POCUS on a small neck, with a cervical collar in place, or if there is subcutaneous emphysema (air obscures structures below).
Depth: Airway POCUS is not able to determine the exact depth of ETT within the trachea, but can be a good surrogate of position:
- Visualization of the ETT cuff at the suprasternal notch using a linear probe in the transverse orientation correlated with the ETT depth on chest x-ray in 57/60 children (Cl, 86-98%) in a single center, prospective observational study [11]
- If you are concerned about a mainstem bronchus intubation, slowly pull back on the ETT to see if the lung opposite the main stem intubation starts sliding. If the depth of the tube at the gums/teeth/lips seems appropriate and one side still does not have sliding, there may be a pneumothorax on that side.
False negative for ETT placement: In the rare patient with thyroid gland calcifications, there may falsely appear to be 2 shadowing structures (double tract sign), even when the ETT is correctly in the trachea. Calcifications shadow. This can be anticipated with pre-scanning the neck before intubation.
False positive for ETT placement: If the esophagus is structurally immediately posterior to the trachea, you wouldn’t see a “double tract” sign if the ETT is in the esophagus. But you should have other signs soon if the ETT is in the wrong place such as lack of ETCO2 and lack of breath sounds.
Lack of lung sliding may not always be due to pneumothorax or right mainstem ETT intubation. Other explanations include:
- ETT obstruction
- Apnea in a spontaneously breathing patient or no breath being delivered to a patient who is intubated.
- Lack of sliding or “barcode” (on M-mode) should be interpreted with caution in patients who have parenchymal lung disease or pleurodesis (a procedure where the pleura is surgically or mechanically adhered to the chest wall) making the lung appear not to slide. These patients may not have pneumothorax nor a main stem intubation on the other side.

Literature Review

Adult Literature

In a metanalysis of 30 adult studies assessing the use of POCUS for ETT placement confirmation, the overall sensitivity was 0.98 (95% CI 0.97–0.99) and specificity was 0.96 (95% CI 0.90–0.98) [4].

Other studies have evaluated using various techniques for POCUS evaluation of ETT placement, with no clear winner (Table 1).

Variable	Source	Findings	Recommendation
Probe type: Linear vs Curvilinear	Sahu 2020 [4]	No difference	Linear probe
Technique: Static vs Dynamic	Sahu 2020 [4]	No difference	Static technique
Probe placement: Transverse at suprasternal notch Longitudinal at cricoid or thyroid cartilage	Lonchena 2017 [5]	Successful ETT visualization Suprasternal notch: 100% Cricoid: 70% Thyroid: 40%	Place probe transverse in suprasternal notch in the anterior neck

Variable

Source

Findings

Recommendation

Probe type: Linear vs Curvilinear

Sahu 2020 [4]

No difference

Linear probe

Technique: Static vs Dynamic

Sahu 2020 [4]

No difference

Static technique

Probe placement:

Transverse at suprasternal notch
Longitudinal at cricoid or thyroid cartilage

Lonchena 2017 [5]

Successful ETT visualization

Suprasternal notch: 100%
Cricoid: 70%
Thyroid: 40%

Place probe transverse in suprasternal notch in the anterior neck

Table 1: Published studies in the adult population, comparing different techniques for confirming ETT placement with POCUS.

Pediatric Literature

The pediatric literature for the application of POCUS to evaluate ETT placement is not as robust compared to adult studies; however, it is still compelling. A systematic review by Lin et al. in 2016 [3] included studies that evaluated intubations using direct visualization of tube tip in trachea, diaphragmatic movement and/or lung sliding. All modalities had high sensitivities though the esophageal intubation rates included in the studies were relatively low (Table 2).

Study	Endotracheal Intub	Esophageal Intub	POCUS Technique Used	Sensitivity	Specificity
Galicinao 2007 [6]	50	1	Direct visualization of tube tip in trachea	1.00 (0.93-1.00)	1.00 (0.03-1.00)
Alonso Quintela 2014 [7]	31	5	Direct visualization of tube tip in trachea	0.92 (0.75-0.99)	1.00 (0.48-1.00)
Hsieh 2004 [8]	61	2	Diaphragmatic or lung pleural movement	1.00 (0.94-1.00)	1.00 (0.16-1.00)
Kerrey 2009 [9]	127	0	Diaphragmatic or lung pleural movement	1.00 (0.97-1.00)	Not reported

Table 2: Summary of pediatric studies that evaluated using POCUS for ETT confirmation by direct visualization of the tube in the trachea over the anterior neck or indirectly by assessing for diaphragmatic or pleural movement.

Another systematic review of using POCUS to confirm ETT position in the pediatric population by Jaeel et al [10], found that POCUS was comparable to confirming ETT placement by x-ray and capnography for patients outside the neonatal intensive care unit. They concluded that POCUS agreed with x-ray or capnography confirmation in 83-100% of cases. Compared to x-rays, POCUS had a sensitivity of 91-100%.

Case Resolution

After administration of fentanyl, midazolam, and rocuronium, the patient was intubated with a 4.0 cuffed ETT by direct laryngoscopy with a Macintosh blade.

POCUS was used to confirm ETT placement by the transport team in the community hospital ED. Specifically, the provider directly visualized the in the anterior neck (with a single air-mucosa interface), the presence of bilateral lung sliding, and movement of the diaphragm towards the abdomen with PPV. End tidal CO2 further confirmed accurate placement. Once loaded into the ambulance, the ETT was again confirmed to be in the trachea.

Video 11: POCUS showing bilateral lung sliding

Video 12. POCUS showing diaphragmatic movement down to the abdomen with breathing.

Learn More…

References

Tsung JW, Fenster D, Kessler DO, Novik J. Dynamic anatomic relationship of the esophagus and trachea on sonography: implications for endotracheal tube confirmation in children. Journal of Ultrasound in Medicine. 2012 Sep;31(9):1365-70. PMID 22922616
Tessaro MO, Salant EP, Arroyo AC, Haines LE, Dickman E. Tracheal rapid ultrasound saline test (TRUST) for confirming correct endotracheal tube depth in children. Resuscitation. 2015 Apr 1;89:8-12. PMID 25238740
Lin MJ, Gurley K, Hoffmann B. Bedside Ultrasound for Tracheal Tube Verification in Pediatric Emergency Department and ICU Patients: A Systematic Review. Pediatr Crit Care Med. 2016;17(10):e469-e476. PMID 27487913
Sahu AK, Bhoi S, Aggarwal P, et al. Endotracheal tube placement confirmation by ultrasonography: A systematic review and meta-analysis of more than 2500 patients. J Emerg Med. 2020 Aug 1;59(2):254-64. PMID 32553512
Lonchena T, So S, Ibinson J, Roolf P, Orebaugh SL. Optimization of ultrasound transducer positioning for endotracheal tube placement confirmation in cadaveric model. J Ultrasound Med. 2017 Feb;36(2):279-84. PMID 28072483
Galicinao J, Bush AJ, Godambe SA. Use of bedside ultrasonography for endotracheal tube placement in pediatric patients: A feasibility study. Pediatrics 2007; 120:1297–1303. PMID 18055679
Alonso Quintela P, Oulego Erroz I, Mora Matilla M, et al: [Usefulness of bedside ultrasound compared to capnography and radiograph for tracheal intubation]. An Pediatr (Barc) 2014; 81:283–288. PMID 24560730
Hsieh KS, Lee CL, Lin CC, Huang TC, Weng KP, Lu WH. Secondary confirmation of endotracheal tube position by ultrasound image. Crit Care Med. 2004 Sep;32(9 Suppl):S374-7. PMID 15508663
Kerrey BT, Ceis GL, Quinn AM. A prospective comparison of diaphragmatic ultrasound and chest radiography to determine endotracheal. Pediatrics. 2009;123:1039-43. PMID 19414520
Jaeel P, Sheth M, Nguyen J. Ultrasonography for endotracheal tube position in infants and children. Eur J Pediatr. 2017 Mar;176(3):293-300. PMID 28091777
Uya A, Gautam NK, Rafique MB, et al. Point-of-Care Ultrasound in Sternal Notch Confirms Depth of Endotracheal Tube in Children. Pediatr Crit Care Med. 2020;21(7):e393-e398. PMID 32168296

Additional Reading

Adhikari S, Blaivas M. The Ultimate Guide to Point-of-Care Ultrasound-Guided Procedures. 1st Ed. Springer Nature; 2020.
Blaivas M, Tsung JW. Point-of-care sonographic detection of left endobronchial main stem intubation and obstruction versus endotracheal intubation. J Ultrasound Med. 2008;27(5):785-789. doi:10.7863/jum.2008.27.5.785. PMID 18424655
Chou EH, Dickman E, Tsou PY, et al. Ultrasonography for confirmation of endotracheal tube placement: a systematic review and meta-analysis. Resuscitation. 2015;90:97-103. doi:10.1016/j.resuscitation.2015.02.013. PMID 25711517
Hoffmann B, Gullett JP, Hill HF, et al. Bedside ultrasound of the neck confirms endotracheal tube position in emergency intubations. Ultraschall Med. 2014;35(5):451-458. doi:10.1055/s-0034-1366014. PMID 25014479
Lahham S, Baydoun J, Bailey J, et al. A Prospective Evaluation of Transverse Tracheal Sonography During Emergent Intubation by Emergency Medicine Resident Physicians. J Ultrasound Med. 2017;36(10):2079-2085. doi:10.1002/jum.14231. PMID 28503749
Marciniak B, Fayoux P, Hébrard A, et al. Airway management in children: ultrasonography assessment of tracheal intubation in real time?. Anesth Analg. 2009;108(2):461-465. doi:10.1213/ane.0b013e31819240f5. PMID 19151273
Mori T, Nomura O, Hagiwara Y, Inoue N. Diagnostic Accuracy of a 3-Point Ultrasound Protocol to Detect Esophageal or Endobronchial Mainstem Intubation in a Pediatric Emergency Department. J Ultrasound Med. 2019;38(11):2945-2954. doi:10.1002/jum.15000. PMID 30993739
Prada G, Vieillard-Baron A, Martin AK, et al. Tracheal, Lung, and Diaphragmatic Applications of M-Mode Ultrasonography in Anesthesiology and Critical Care. J Cardiothorac Vasc Anesth. 2021;35(1):310-322. doi:10.1053/j.jvca.2019.11.051. PMID 31883769
Sethi AK, Salhotra R, Chandra M, Mohta M, Bhatt S, Kayina CA. Confirmation of placement of endotracheal tube – A comparative observational pilot study of three ultrasound methods. J Anaesthesiol Clin Pharmacol. 2019;35(3):353-358. doi:10.4103/joacp.JOACP_317_18. PMID 31543584
Sim SS, Lien WC, Chou HC, et al. Ultrasonographic lung sliding sign in confirming proper endotracheal intubation during emergency intubation. Resuscitation. 2012;83(3):307-312. doi:10.1016/j.resuscitation.2011.11.010. PMID 22138058
Singh M, Chin KJ, Chan VW, Wong DT, Prasad GA, Yu E. Use of sonography for airway assessment: an observational study. J Ultrasound Med. 2010;29(1):79-85. doi:10.7863/jum.2010.29.1.79. PMID 20040778
Weaver B, Lyon M, Blaivas M. Confirmation of endotracheal tube placement after intubation using the ultrasound sliding lung sign. Acad Emerg Med. 2006;13(3):239-244. doi:10.1197/j.aem.2005.08.014. PMID 16495415

By Nichole McCollum, MD|2022-04-30T19:47:20-07:00May 2, 2022|ALiEMU, Pediatrics, PEM POCUS, Radiology, Ultrasound|

SmilER 104: Pericoronitis and Dry Socket

This fourth and final installment in the SmilER series covers the diagnosis and management of 2 common dental conditions that present to the emergency department: pericoronitis and dry socket.

Author: Richard Ngo, DMD
Editors: Cameron Lee, DMD, MD; Andrew Eyre, MD, MS-HPEd
Series Editor: Chris Nash, MD

How well did you learn the material? Go to ALiEMU to take the multiple-choice quizzes to receive your badges and certificates.

Learning Objectives

Understand diagnostic criteria of pericoronitis and alveolar osteitis (dry socket).
Understand treatment modalities for patients with pericoronitis and alveolar osteitis (dry socket).
Name some of the pharmacological adjuncts to aid in recovery.
Review key points to include in discharge instructions.

Pericoronitis

Diagnosis

Patients may present to the ED with pericoronitis, an inflammation of the gingival soft tissue overlying a mandibular third molar. This soft tissue is subject to trauma from the patient biting down and may lead to pericoronitis due to normal oral flora. Patients with compromised host defenses may more easily develop pericoronitis. Repeated trauma to the operculum, the soft tissue overlying a partially erupted tooth, may lead to increased swelling more easily subject to subsequent trauma—a vicious cycle leading to worsening pain and erythematous swelling. Food may also become entrapped under the soft tissue due to difficulty maintaining oral hygiene.

Pericoronitis is a clinical diagnosis and does not require imaging.

Pericoronitis over an impacted right mandibular third molar exhibiting inflammation, erythema, and swelling

Pericoronitis

Treatment, discharge, and follow up

Irrigation: In the emergency department and as an outpatient, irrigation of food debris under the operculum using chlorhexidine or normal saline can acutely reduce bacterial counts.
Antibiotics: The patient can be prescribed penicillin, or clindamycin if allergic to penicillin. If not treated, pericoronitis may result in a localized soft tissue infection (see SmilER 103).

The patient should follow-up with an outpatient dentist to prevent recurrent infections. This typically involves the patient undergoing definitive treatment, that is, extraction of the offending tooth.

Dry Socket

Diagnosis

Dry socket, also known as alveolar osteitis, is moderate to severe pain experienced after dental extraction due to exposure of bony surfaces. The pain typically begins 3-5 days following a tooth extraction. Although the cause is unclear, it is thought to be related to fibrinolytic activity within the extraction socket, which leads to lysis of the developing blood clot. The subsequent exposure of bone leads to moderate to severe pain that may be dull and aching. This pain may radiate to the ipsilateral ear. Associated symptoms include a foul odor or taste. Although dry socket is rare (2%) following routine dental extractions, it is more commonly associated with extraction of the mandibular third molars.

Dry socket after tooth extraction

Dry socket illustration for exposed bone and nerve after a blood clot is dislodged

Treatment, discharge, and follow up

Treatment of a dry socket is relatively simple. The premise is to NOT dislodge any newly forming blood clot, which serves as a protective covering.

Irrigate the socket with sterile saline
Gently suction away the excess saline, but do not go too deep into the socket as to evacuate the developing blood clot. The area also should NOT be curetted, as this will often worsen and possibly dislodge beneficial blood clots.
Insert a medicated dry socket dressing (iodoform gauze) into the socket. These may be available in your emergency department or, alternatively, can be obtained from the pharmacy or as a commercial preparation from a dental supply company. Ingredients in this dressing include: eugenol to help with pain, topical anesthetic such as benzocaine, and a carrying vehicle such as balsam of Peru. Upon application, the patient should experience immediate relief within 5 minutes. Unfortunately, many emergency departments do not stock dry socket paste or Dressol-X. An alternative is ribbon gauze or Gelfoam impregnated with eugenol, iodine, or oil of cloves.

The patient should follow-up with an outpatient dentist or oral surgeon within 2 days to have their dry socket dressing changed every other day for the next 3-5 days.

References

Hupp J, Ellis E, Tucker M. Contemporary Oral and Maxillofacial Surgery. Elsevier; 2019.
Berman L, Blanco L, Cohen S. A Clinical Guide to Dental Traumatology. Mosby; 2006.
Kademani Deepak. Atlas of Oral and Maxillofacial Surgery. Saunders; 2015.

SmilER Series

The purpose of the SmilER series on dental trauma and infection management is to teach fundamental principles, pearls, and pitfalls in the care for dental patients in the emergency department. As many as 1.5% of ED visits are dental-related¹ and many emergency physicians have expressed the need for more comprehensive training in the oral cavity. This series was created as an introductory guide on the management of patients who report to the ED with dental-related conditions.

All information has been expert peer-reviewed by an oral and maxillofacial surgeon.

By Richard Ngo, DMD|2023-02-07T13:43:30-08:00Oct 6, 2021|ALiEMU, Dental, SmilER|

SmilER 103: Odontogenic Infections

This third module for the SmilER series covers the diagnosis and management of odontogenic infections seen in the emergency department (ED). What anatomical structures should be avoided? When is imaging necessary? What is the discharge plan?

Author: Richard Ngo, DMD
Editors: Cameron Lee, DMD, MD; Andrew Eyre, MD, MS-HPEd
Series Editor: Chris Nash, MD

How well did you learn the material? Go to ALiEMU to take the multiple-choice quizzes to receive your badges and certificates.

Learning Objectives

Understand the major classifications and diagnostic criteria of odontogenic infections.
Understand the indications and contraindications for computed tomographic (CT) imaging as well as incision and drainage (I&D).
- List the materials that are required to perform an incision and drainage.
- List some of the potential complications of incision and drainage.
Name some of the pharmacological adjuncts to aid in recovery.
Review key points to include in patient discharge instructions.

Introduction to Odontogenic Infections

Evolution of odontogenic infections, progressing from caries, pulp inflammation, to abscess formation

Odontogenic infections are infections that are dental in origin. Infections start as carious (cavitary) lesions of the dentition that spread through the pulpal tissue to develop an abscess, a purulent collection that begins at the tooth’s root. From here, the abscess may extend through the mandible or maxilla to other regions of the mouth, face, and the rest of the body through the fascial planes of the head and neck.

(A) Periradicular (around the root) infection in a maxillary incisor with the root apex close to the facial aspect of the maxilla results in erosion of the facial cortex and an abscess in the vestibular space. (B) Maxillary incisor with the root apex closer to the palatal cortex, increasing the likelihood of palatal cortical erosion and palatal abscess. [1]

Abscess vs Cellulitis

An abscess is a localized, fluctuant mass that can be palpated upon physical examination. In contrast, cellulitis is characterized by diffuse induration without purulence. In both cases, patients may be febrile and may exhibit erythema or warmth of the infected site. Abscesses benefit from incision and drainage treatment, while antibiotics alone are sufficient for cellulitis.

Incision and Drainage (I&D)

For abscesses, the most important therapeutic intervention is the I&D of purulent material. The technique and approach is similar to the I&D of skin and soft tissue abscesses in other parts of the body. For odontogenic infections, I&D also changes the previously anaerobic environment into an aerobic one, thus making it difficult for anaerobic microbes to survive. As with skin and soft tissue abscesses, antibiotic therapy is a necessary adjunct to proper drainage.

Buccal space abscess spontaneously draining through the skin of the cheek (path of least resistance) [1]

Head and Neck Anatomy

Potential fascial planes for infection

Fascial Planes

The head and neck regions have many fascial planes containing potential spaces by which pus or cellulitis from odontogenic infections may spread. Major anatomic groups include: the midface, cheek and lateral face, mandible and below, and pharyngeal and cervical areas. Once eroded through bone, an infection can express itself in various places depending on the the relationship of muscle attachments to the site of perforation. Regions beyond the local buccal and vestibular spaces of the oral cavity should be escalated to specialty care, given anatomy complexity and potential risk for airway compromise or irreversible damage to anatomic structures.

Facial anatomy and boundaries of the masticator space

Masticator Space Abscess

One example of a deep space that may become infected and requires specialty consultation is the masticator space. The masticator space is a general term that includes the any of the following spaces:

Pterygomandibular space
Submasseteric space
Superficial temporal space
Deep temporal space

The boundaries of the masticator space consists of the muscles of mastication, which including the following:

Masseter muscle
Medial and lateral pterygoid muscles
Temporalis muscle

The superficial and deep temporal spaces are separated from each other by the temporalis muscle. The lateral pterygoid muscle divides the pterygomandibular space from the infratemporal portion of the deep temporal space. The zygomatic arch divides the submasseteric space from the superficial temporal space. Abscesses within any of the components of the masticator space will require surgical drainage in an operating room under general anesthesia and should not be attempted in the ED.

Axial cross-section view of fascial space infections

The above axial cross-section diagram marks other extraoral regions which require specialty consultation. The fascial planes of the head and neck region may serve as potential pathways for the spread of infection into deeper spaces. As an example, the retropharyngeal space (yellow area in diagram above) allows for the potentially dangerous extension of infection into the mediastinum.

Diagnosis of Odontogenic Infections

Part 1: History

Proper diagnosis of odontogenic infection in the ED begins with a thorough medical and dental history (see the Oral Examination and Local Anesthesia course). Additionally, ask about the course and progression of the swelling, dysphagia, odynophagia, dyspnea, foul breath or taste, and any immunocompromising conditions.

Part 2: Examination

Suction, irrigate, and examine the oral cavity thoroughly. Palpate any intraoral or extraoral masses to assess fluctuance or induration. Also note the following:

Location of swelling and dental pain
Floor of mouth elevation or induration
Uvular deviation
Periorbital swelling
Orbital proptosis

Measure the maximal incisal opening by asking patients to open their mouths as wide as possible; this is the greatest distance between the incisal edge of the maxillary central incisor and the incisal edge of the mandibular central incisor. A normal adult mouth opening is between 30-40 mm. Trismus, or reduced mouth opening, should raise concern for a potential deep space infection.

Measuring the maximal incisal opening, between the incisal edges of upper and lower central incisors.

A crucial odontogenic infection-related physical exam finding includes blunting of the inferior border of the mandible at the body; this is significant facial swelling that prevents the provider from palpating the bony structures at the body of the mandible.

Anatomy of the mandible. An important exam finding includes swelling of the soft tissues overlying the body of the mandible.

Part 3: Imaging

Computed tomography (CT) imaging is indicated if there is concern for an odontogenic infection involving a deep fascial space. Two physical exam findings help predict when CT imaging is warranted [2].

Blunting of inferior border of the mandibular body
Trismus, as determined by maximum incisal opening <25 mm

Algorithm to determine whether CT imaging for odontogenic infection is necessary

If CT is not indicated, a Panorex panoramic radiograph is sufficient.

Specialty Consultation

It can be challenging to determine when a patient’s odontogenic infection warrants specialist consultation in the ED, operative treatment, or inpatient admission.

High risk odontogenic infections

The patient will require inpatient admission and likely operative treatment for these following conditions in the setting of an odontogenic infection:

Involvement of the airway or deeper fascial spaces
Rapid progression of the infection
Need for general anesthesia
Dehydration or the inability to take fluids orally
Trismus
Immunocompromised status
Lack of improvement on oral antibiotics

These patients should be monitored for progression of the infection, as cases may rapidly progress to life-threatening conditions. If the infection is evident on the skin, mark the edge of the erythematous regions of the infection to monitor spread.

Odontogenic infections which do NOT require specialty consultation

Intra-oral maxillary and mandibular vestibular and buccal space swellings are infections limited to relatively safe, low-risk areas. These abscesses are amenable to incision and drainage by the emergency physician under local anesthesia. These are fascial spaces that will not cause airway obstruction and generally do not require general anesthesia or extraoral incisions to achieve adequate drainage. In these cases, patients normally do not complain of trismus, difficulty breathing, or swallowing. CT imaging is usually unnecessary.

1. Vestibular Abscess

Vestibular abscess, localized within the oral cavity and without spread to more dangerous fascial planes

Vestibular abscesses are infections that spread through bone to buccal tissues when the apex of the involved tooth is within the confines of the buccinator muscle attachment. The infection remains between the oral mucosa and the nearby facial muscle.

2. Buccal Abscess

Buccal space infection

Buccal infection

3. Buccal Space Abscess

The buccal space lies superficial to the buccinator muscle and deep to the overlying skin and subcutaneous tissue. In these cases, the involved tooth’s apex is either superior or inferior to the insertion of the buccinator muscle. This potential space may become involved via infection of maxillary or mandibular molars.

Difference between a vestibular space abscess (A) and a buccal space abscess (B). Coronal view of a right maxillary tooth.

A) When the tooth root apex is within the confines of the attachment for the buccinator muscle (in red), a vestibular space abscess localized medial to the buccinator muscle results.

B) When the tooth root apex is outside of the confines of the attachment for the buccinator muscle (in red), a buccal space abscess localized lateral to the buccinator muscle results.

Odontogenic infections which DO require specialty consultation

Progression of infections to deeper spaces beyond the vestibular and buccal spaces increases the severity of the infection and thus requires specialty consultation. Indications for specialty consultation include any of the following:

The spread of infection to potentially dangerous fascial spaces, potentially leading to airway compromise
Difficulty swallowing
Trismus
Systemic signs of infection, such as a toxic appearance, respiratory distress, or altered mental status

In these cases, CT imaging is usually needed to determine the location and extent of the infection.

What deep space areas are especially dangerous?

Dangerous fascial planes include infection which spread:

Beyond the alveolar process (such as to the submental, sublingual, or submandibular spaces)
To the palatal spaces (medial relative to the maxillary dentition)
To the masticator space involving the muscles of mastication
To the more posterior oropharyngeal/retropharyngeal spaces
To the superiorly-located sinuses or orbital spaces
To any nearby vital structures such as major nerves and arteries (mental, lingual, facial, and ophthalmic bundles).

When in doubt, CT imaging should be obtained to determine proximity to nearby vital structures. In more severe cases, odontogenic infections may potentially lead to but are not limited to cavernous sinus thrombosis, Ludwig’s angina (the bilateral involvement of the submandibular, sublingual, and submental spaces), sinusitis, brain abscess, or mediastinitis. These more severe cases often require airway management, CT imaging, IV antibiotics, or emergent I&D in the operating room by specialty surgical services.

Examples of High-Risk Cases

The following figures indicate common regions involved in odontogenic infections for which escalation of care with specialty consultation is recommended. These complex infections include: palatal space abscesses on the palate of the mouth medial to the maxillary dentition, sublingual and submandibular space abscesses inferior to the tongue and floor of mouth, and abscesses that extends superiorly to involve the sinuses or orbits. To reiterate, any abscess requiring an extra oral approach for management requires specialist consultation.

Abscesses in the Mandibular Premolar Region:

Abscesses located in the mandibular premolar region are located near the mental neurovascular bundle. Those that require I&D need a cautious approach to avoid this vital structure. These may be better served by drainage by a consulting dentist or oral surgeon.

Mental neurovascular bundle along the mandible exits near the left mandibular canine/first pre-molar

Palatal Space Abscesses:

Found medial to the maxillary dentition. I&D should be escalated to specialty care to avoid damaging the greater and lesser palatine neurovascular bundles.

Incision and drainage of palatal space abscess

Left palatal space abscess (medial to the maxillary dentition)

Sublingual Abscesses:The sublingual space lies between the oral mucosa and the mylohyoid muscle and can become infected from the mandibular premolar and first molar teeth. I&D should be escalated to specialty care as abscesses in this space are at high risk for rapid spread and airway compromise.
Sublingual abscess
Submandibular Abscesses:
The submandibular space lies between the mylohyoid muscle and anterior layer of the deep cervical fascia, just deep to platysma muscle. It includes the lingual and inferior surfaces of the mandible below the mylohyoid muscle attachment. I&D should be escalated to specialty care as abscesses in this space are at high risk for rapid spread and airway compromise.

Submandibular abscess Example of a submandibular abscess

Incision and Drainage Procedure

Potential risks for incision and drainage (I&D) should be discussed with the patient and informed consent obtained. These risks include but may not be limited to pain, bleeding, swelling, scarring, damage to adjacent anatomic structures, nerve damage, and the need for additional procedures.

Steps

Examine the oral cavity for any foreign material.
Suction out any blood, saliva, and purulence.
Irrigate the oral cavity with copious normal saline.
Administer local anesthesia should be administered via a regional block and/or into the mucosa adjacent to the site of infection. Be careful not to pass the needle from infected to uninfected tissue to avoid the unintended inoculation of offending bacteria. Additional anesthesia may be required in the setting of infection. If the initial level of anesthesia is suboptimal, partially drain the abscess and irrigate to remove some of the pus. This can improve the acidic pH of the infection, allowing for additional local anesthetic to be more effective.
Palpate the abscess to determine where the incision would obtain maximum drainage.
Make a 1- to 2-cm incision perpendicular to the underlying bone at the height of fluctuance, while avoiding any major anatomical structures.
- Maxillary vestibular abscesses: Placing the incision in a dependent (inferior) position prevents incomplete drainage. Upon evacuation of pus, a syringe can be used to collect cultures to be sent for sensitivity analysis. Submucosal spreading to break open any loculations with a curved hemostat should be performed. Finally, irrigate the surgical site copiously.

For a maxillary vestibular abscess, an incision at a dependent, inferior position (green arrow) helps to prevent incomplete drainage from the pooling of the purulence on the inferior aspect of the abscess cavity. An incision at a non-dependent, superior position (red arrow) may lead to pooling of purulence and inadequate drainage.

Incision and drainage technique for vestibular abscess. (A) Periapical infection of a mandibular premolar (note buccal cortical erosion superior to the buccinator muscle attachment). (B) Incision made into fluctuant swelling to the depth of the abscess cavity. (C) Curved hemostat used in opening motion in various directions to break loculations of purulence within the abscess cavity. (D) Optional: insertion of a Penrose drain (1 cm diameter) into the depth of the abscess cavity. (E) Optional: suturing of the drain with a single nonabsorbable suture (3-0 silk).

Discharge and Follow-Up

Oral Hygiene

Patients should be prescribed chlorhexidine 15 mL swish and spit, twice daily for 1 week.

Antibiotics

Mixed aerobic and anaerobic bacteria cause most odontogenic infections. Antibiotics are an adjunct but not a replacement for incision and drainage in odontogenic abscess management. Antibiotics are particularly important for immunocompromised patients.

Oral amoxicillin 500 mg TID for 3-7 days
Alternative: Oral penicillin V potassium 500 mg QID for 3-7 days
If first-line treatment fails: Either broaden the antibiotic therapy by adding oral metronidazole 500 mg TID for 7 days, or discontinue first-line treatment and prescribe oral amoxicillin 500 mg and clavulanate 125 mg (Augmentin) TID for 7 days.

What if the patient has a penicillin allergy?

Inquire whether the patient has a history of anaphylaxis, angioedema, or hives with penicillin, ampicillin, or amoxicillin.
If the patient does not have any history of these severe allergic reactions, prescribe oral cephalexin 500 mg QID for 3-7 days.
If the patient does have such an allergic history, then prescribe oral azithromycin with a loading dose of 500 mg for one day, followed by 250 mg for an additional 4 days. An alternative to this would be oral clindamycin 300 mg QID for 3-7 days. If first-line treatment fails, then broaden antibiotic therapy to by adding oral metronidazole 500 mg TID for 7 days.

Pain Management

Postoperative pain can be managed with ibuprofen and/or acetaminophen. Peak swelling and inflammation is expected roughly 48 hours post-procedurally.

Follow-up

The patient must be instructed to follow up with an outpatient dentist as soon as possible to address the underlying cause of the infection. A root canal treatment or extraction of the offending tooth will likely be necessary to achieve source control of the infection. Failing this, the patient is likely to return to the ED with a recurring infection. Reasons for return to the hospital may include but are not limited to inadequate drainage with residual undrained loculations, spread of infection to deeper fascial planes, inappropriate antibiotic choice or dosage, or issues related to patient compliance.

References

Hupp J, Ellis E, Tucker M. Contemporary Oral and Maxillofacial Surgery. Elsevier; 2019.
Christensen BJ, Park EP, Suau S, Beran D, King BJ. Evidence-Based Clinical Criteria for Computed Tomography Imaging in Odontogenic Infections. J Oral Maxillofac Surg. 2019;77(2):299-306. PMID: 30347202
Berman L, Blanco L, Cohen S. A Clinical Guide to Dental Traumatology. Mosby; 2006.
Kademani D. Atlas of Oral and Maxillofacial Surgery. Saunders; 2015.

SmilER Series

All information has been expert peer-reviewed by an oral and maxillofacial surgeon.

By Richard Ngo, DMD|2022-09-22T06:43:34-07:00Sep 30, 2021|ALiEMU, Dental, SmilER|

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